Cosmo has no father. His mother has lunacy fringe dependency issues, demonstrated by her constant beratement and sabotage of her son, Cosmo.
Cosmo, as a result, lives a life of self-deprecation and attention gathering, enter his desire for Wanda's company, and his inability to accept Jimmy's mortality.

Wanda is a very successful fairy who cares too much. As a result, she feels that she cannot leave the broken individuals, Cosmo and Jimmy, at her own emotional expense.

Jimmy's father is a smart man whose ambitions came to a sudden halt when his wife accidentally conceived Jimmy. As a result, he constantly strives to regain his youthful visage--hipness and success. He recognizes the success of his neighbors, that they don't have kids, and therefore constantly blames his failure on his child, while also aiming to achieve success in greater measure than his neighbors.

There's an episode where Timmy is harrassed by a third party who continuously calls him Jimmy.

There's an episode where Jimmy catches the bitch red handed in a comic book store wearing a disguise and purchasing a comic book.

There're many episodes where she displays affection for Jimmy. A great example is when he invites many people to his house for a big party and abuses Cosmo and Wanda to get party effects. Those invited arrive at Jimmy's house to find that it is exactly that, a house. Here it is important to note that only the viewer, Jimmy, and Jimmy's godparents know that Jimmy does not have a mansion, because reasons.

It is also important to note that everybody, when they see that Jimmy's house is indeed just a house--not a mansion--they all leave in disappointment. That is except for one person, Jimmy's crush.

While being chauffeured to Jimmy's, Jimmy's crush was looking out the window at Jimmy's house. Even having known that Jimmy did not own a mansion, she still wanted to celebrate with Jimmy. But, when the crowd disapproves of Jimmy's living establishment, Jimmy's crush feels that she can't but follow suit and leave. And yet she is the only one to say goodbye. She, bless her bitchy heart, sneaks back to give Jimmy a kiss and verbally understate her affection for him.